Loads when you scroll to it. Unloads after 5 minutes in the background.

Symbol & Footprint

Schematic Symbol

Open full view ↗
Loads when you scroll to it. Unloads after 5 minutes in the background.

PCB Footprint

Open full view ↗
Loads when you scroll to it. Unloads after 5 minutes in the background.
Loads when you scroll to it. Unloads after 5 minutes in the background.
Download PDF
Contents

README

markdown

RT9040GQW

Richtek Tech · Linear Voltage Regulators (LDO) · WDFN-10(3x3)

RT9040GQW from Richtek Tech, in a WDFN-10(3x3). Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin Name Type Function
1 REFIN input Reference input that sets the regulated output voltage, with REFIN above 0.39V required for the regulator to be enabled.
2 VIN power_in Supply voltage for the LDO, specified at 1.1V to 3.5V.
3 VOUT power_out Power output of the LDO that feeds the DDR termination bus and needs at least 20µF of ceramic output capacitance.
4 PGND power_in Power ground return for the LDO output stage.
5 SENSE input Voltage sense input for the LDO, connected to the positive terminal of the output capacitor or the load.
6 REFOUT power_out Reference output that sources or sinks up to 10mA and should be bypassed to GND with a 0.1µF ceramic capacitor.
7 EN input Chip enable that is connected to SLP_S3 in DDR VTT applications and otherwise works as the ON/OFF function.
8 GND power_in Signal ground that connects to the negative terminal of the output capacitor.
9 PGOOD output Open-drain power good output that indicates whether the output is in regulation.
10 VCNTL power_in Supply input of 2.5V, 3.3V or 5V that requires a ceramic decoupling capacitor between 1µF and 4.7µF.
11 GND power_in Exposed pad that is the signal ground and must be soldered to a large PCB ground for maximum power dissipation.

Key specifications

Parameter Value
Manufacturer Richtek Tech
Package WDFN-10(3x3)
Category Power Management ICs
Pins 11

Electrical characteristics

Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).

Parameter Symbol Min Typ Max Unit Conditions Page
VCNTL Supply Current IVCNTL 0.9 2 mA VEN = 3.3V, No Load 3
VCNTL Shutdown Current ISHDN_VCNTL 65 80 A VEN = 0V, VREFIN = 0, No Load 3
VCNTL Shutdown Current ISHDN_VCNTL 200 500 A VEN = 0V, VREFIN > 0.4V, No Load 3
VIN Supply Current IVIN 2 mA VEN = 3.3V, No Load 3
VIN Shutdown Current ISHDN_VIN 0.1 50 A VEN = 0V, No Load 3
REFIN Input Current IREFIN 1 A VEN = 3.3 V 3
Offset Voltage of Output DC Voltage (DDRI) VVOTOL -10 10 mV VIN = 2.5 V, VREFOUT = 1.25 V (DDRI), IOUT = 0A 3
Offset Voltage of Output DC Voltage (DDRII) VVOTOL -10 10 mV VIN = 1.8 V, VREFOUT = 0.9V (DDRII), IOUT = 0A 3
Offset Voltage of Output DC Voltage (DDRIII) VVOTOL -10 10 mV VIN = 1.5 V, VREFOUT = 0.75V (DDRIII), IOUT = 0A 3
VOUT Load Regulation VLOAD -15 15 mV -2A < IOUT < 2A 3
Supply Input Voltage VCNTL 2.375 5.5 V 3
Supply Input Voltage VIN 1.1 3.5 V 3
Junction Temperature Range -40 125 °C 3
Ambient Temperature Range -40 85 °C 3
Supply Input Voltage VIN, REFIN, VCNTL 6 V 3
Enable Voltage EN 6 V 3
Power Dissipation PD @ TA = 25°C PD 1.429 W WDFN-10L 3x3, TA = 25°C 3
Package Thermal Resistance θJA θJA 70 °C/W WDFN-10L 3x3 3
Package Thermal Resistance θJC θJC 8.2 °C/W WDFN-10L 3x3 3
Lead Temperature (Soldering) 260 °C 10 sec. 3
Junction Temperature 150 °C 3
Storage Temperature Range -65 150 °C 3
ESD HBM 2 kV Human Body Model 3
ESD MM 200 V Machine Model 3
VOUT Source Current Limit ILIM_VOUT_sr 3.5 5.5 A VCNTL = 5V (VOUT in PGOOD window) 4
VOUT Sink Current Limit ILIM_VOUT_sk 3.5 5.5 A VCNTL = 5V (VOUT in PGOOD window) 4
VOUT Discharge Resistance RDISCHARGE 18 25 VREFIN = 0V, VOUT = 0.3V, VEN = 0V 4
VOUT PGOOD Threshold VTH_PGOOD 23.5 20 17.5 % PGOOD window lower threshold with respect to REFOUT 4
Output Low Voltage VLOW_PGOOD 0.4 V ISINK = 4mA 4
PGOOD Leakage Current ILEAKAGE_PGOOD 1 A VSENSE = VREFIN (PGOOD high impedance), PGOOD = VCNTL + 0.2 V 4
REFIN Voltage Range VREFIN 0.5 1.8 V 4
REFIN Under Voltage Lockout VUVLO_REFIN 360 390 420 mV REFIN Rising 4
REFOUT Voltage Tolerance to VREFIN VTOL_REFOUT -15 15 mV 10mA < IREFOUT < 10mA, VREFIN = 1.25 V 4
REFOUT Source Current Limit ILIM_REFOUT_sr 10 40 mA VREFOUT = 0V 4
REFOUT Sink Current Limit ILIM_REFOUT_sk 10 40 mA VREFOUT = VIN 4
UVLO Threshold VUVLO_VCNTL 2.2 2.3 2.375 V Wake up 4
High-Level Input Voltage VIN_H 1.7 V Enable 4
Low-Level Input Voltage VIN_L 0.3 V Enable 4
Logic Input Leakage Current ILEAKAGE_EN -1 1 A Enable 4

CAD (KiCad official)

  • Symbol: RT9040GQW
  • Footprint: Package_DFN_QFN:WDFN-10-1EP_3x3mm_P0.5mm_EP1.8x2.5mm
  • 3D model: WDFN-10(3x3) (KiCad packages3D, STEP)
  • 3D model files: rt9040gqw-etched.step / rt9040gqw-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); rt9040gqw.step / rt9040gqw.glb are the bare package body.

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

  • Datasheet: Richtek Tech datasheet (11 pp, sha256 13baae5203f359c6, retrieved 2026-10-27, tier: manufacturer)
  • Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-haiku-5-5 (text), consensus off (skipped (clean text read)), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
  • CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF